Scroll-less chat windows for tabbed chat

[AstroCat]

Ok everything works except for 1 part.

Mouseover Opacity for Backdrop

1. works when you take the mouse and mouseover
2. does not work when chatting appears in the chat area
3. Frame and overall Opacity still do work when chat appears in the chat area

This leads me to believe some part of the code that handles the Backdrop Opacity has been removed.

Any chance of checking it out?

Thanks for your work! Oh and by the way, the old version (non tabbed) of this mod did not have this problem.